Space-saving fire protection: 4 foam proportioners instead of 25 bladder tanks

The fire protection concept of the Nantong University College of Medicine originally envisaged a bladder tank system for the underground parking garage. However, due to the large number of bladder tanks that would be required, the decision was made to switch instead to four FireDos foam proportioners with remote injection system.

The Chinese city of Nantong, located 100 km north of Shanghai, has a population of more than 7 million. Founded in 1912, Nantong Medical College is one of the oldest in China. The university's underground car park is quite extensive and therefore requires a well thought-out fire protection concept.

Initially, a bladder tank solution was considered. However, the Chinese regulation states that foam premix has to reach the sprinkler discharge point within two minutes by an extinguishing water flow of 8 l/s. This means that a centralized bladder tank solution will not fulfill this regulation due to the distance to the discharge points.

• Bladder tanks have to be placed close to the sprinkler discharge points and only a limited area can be protected.
• A total of 25 bladder tanks would be required to effectively protect the entire area from fire.
• As such a bladder tank solution would take up a lot of space — at the expense of the available parking area — Nantong Medical School opted for a more space-saving solution: four FD4000 foam proportioners with remote injection system from FireDos.

The crucial aspect of this fire safety concept is the remote injection of the foam agent. Usually, the foam agent is fed into the extinguishing water flow directly at the water motor outlet of the FireDos proportioner.

With a remote injection system, however,

• the foam concentrate only enters the extinguishing water flow just before the discharge devices.
• Prompt foam discharge shortly after the alarm is guaranteed, a key aspect to fulfill the mentioned Chinese regulation.
• Foam premix can be produced and discharged within a very short time, even when the proportioners are in a centralized location.

Finally, FireDos proportioners with remote injection of the foam agent are an elegant and simple solution to reliably protect the whole underground parking garage from fire.